Dynamo-electric machine.



PATENTED JULY 3, 1906.

M. G. A. LATOUR. DYNAMO ELECTRIC MACHINE.

APPLICATION FILED'NOV. 21, 1902.

Figl.

Fig.2.

Witnesses. lnverfitor.

Marius Charles flrchur" Latour.

UNITED STATES PATENT OFFICE.

MARIUS CHARLES ARTHUR LATOUR, OF SIJVRES, FRANCE, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented July 3. i90

' Application filed November 21, 1902. Serial No. 132,200.

To alt whom, it mag concern:

Be it known that I, MARrUs CHARLES AR- THUR LATOUR, a citizen of France, residing at .Sevres, department of Seine et Oise, France, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

My invention relates to opening electric circuits possessing induction, and has especial reference to the armature-coil circuits of dynamo-electric machines of the commutator type; and its object is to prevent sparking at the commutator when the circuit of a coil is broken in passing under a brush.

It is well known that when an electric cir-' cuit'possessing self-induction is opened extra currents are produced and that the effect of these currents is to raise'abnormally the vol-' tage of the circuit and to produce sparking at the point where the circuit is'opened. When the circuit of an armature-coil which is carrymg current is o ened by-its commutatorsegment leaving t e commutator-brush, arcing is produced by the voltage induced thereby. y my invention I prevent undue rise of voltage, and consequently eliminate detrimental arcing.

My invention will best be understood by reference to the accompanying drawings, in

wlnch Figures 1 and 2 are explanatory diagrams. Fig. 3 is an explanatory diagram. Fig. 4 is a development of an armature electric machine to which my invention is applied, and Figs. 5 and 6 are detail cross-sectional views of two forms of armature-coils. Referring first to Fig- 1, A represents a coil or circuit possessing self-induction. If the circuit of this coil should be opened, as by switch S, the voltage the coil will tend to rise, producing arcing at the switch. This may be prevented by shunting the coil with the'condenser K. This means of absorbing the extra voltage is well known in the art. In place of condenser K a resistance R may be employed, as shown in e resistance. My lnvention consists in substituting for either the capacity or the resistance a shuntcircuit which is itself self-inductive and in so di posing the shunt or auxiliary circuit with of a dynamo-- across the terminals ofnatin -current Fig. 2, the extra currentsinducedin coil A by o ening the circuit being absorbed in heating t reference to the main circuit that the eleccuit upon breaking the main circuit will increase the tendency of the extra current to flow from the mairrwinding through the auxiliary winding.

My invention consists in applying the principle above explained to the armature-coils of dynamo-electric machines.

In Fig. 3, a represents an armature-coil connected to the commutator-segments b b, on which bears the brush B. The circuit of the armature-coil a ossesses self-inductance, and consequently" it is carrying current at the instant one of the commutator-se ments b leaves the brush B extra currents be induced in the armature-coil, resulting in sparking at the commutator-brush. Fig. 4 s ows the develo ment- .of an armature arranged in accord Each turn of the armature-winding D is connected at itsends to the commutator-segments 1). There is also provided the auxiliary winding d, which forms a series of coils each connected in shunt to the coils formed by the main winding and wound o ositely to the coils of the main winding. en the circuit of a coil of the main winding D is ance with my invention.'

broken by the segment to which itis connected, leavlng a commutator-brush, the extra current induced in change in flux, due to the change in current of the coil, will be absorbed by the highresistance auxiliary coil d, connected in shunt to it. Moreover, since the main auxiliary coils are oppositely woundthe extra current induced in the two by the change in flux will be in 0 posite directions. Consequently the induced voltage in the auxiliary coils will assist the flow of extra current from the maincoils through the auxiliary coils.

If the armature is subject to re id changes of magnetic flux, the currents ind iiced in the main coils would heat the auxilia coils too much for practical use. This is t e case in the armature of direct-current dynamo-electric machines. In the rotor of many altermachines of the commutator type, owever, in synchronism with the field induced by the other member of the motor, and consequently the above objection need not be considered in this case.

Figs. 5 and 6 show two constructions of arthe main coil by the the rotor-winding runs almost mature-coils adapted to my invention. In 1 Fig. 5 the main coils D are formed of round wire, and the auxiliary coils d are placed in l the interstices between the turns of the main winding. In Fig. 6 the main winding is shown as formed of a flat bar. The auxiliary winding 65 is placed at the bottom of the slot'and the two taped together to form an integral coil. H g

What I claim as new, and desire to secure by Letters Patent of the United States, isi 1. In dynamo-electric machines provided 1 with a commutator in combination with the main armature-coils an auxiliary circuit connected between the commutator-bars and 1 wound in a way opposite to the winding of l the corresponding main coil'of the armature.

2. In a dynamo-electric machine, main armature-coils, and auxiliary armature-coils 1n inductive relation to said main coils and connected across the commutator-segments,

MARIUS CHARLES ARTHUR LATOUR:

' Witnesses:

EDWARD P. ll/iAOLEAN, 'MATTHEW DINGOE. 

